From 3d97e9a77b6103639d9f9406b27241a41bed389b Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Wed, 24 Feb 2021 16:28:13 +0100
Subject: [PATCH] Properly parse address member.

---
 Changelog.md                                  |  1 +
 libsolidity/parsing/Parser.cpp                | 39 +++++++++++++------
 libsolidity/parsing/Parser.h                  |  2 +
 .../functionTypes/address_member.sol          | 12 ++++++
 4 files changed, 43 insertions(+), 11 deletions(-)
 create mode 100644 test/libsolidity/semanticTests/functionTypes/address_member.sol

diff --git a/Changelog.md b/Changelog.md
index 049d8f22e..536837c71 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -14,6 +14,7 @@ Bugfixes:
  * SMTChecker: Fix missing type constraints on block and transaction variables in the deployment phase.
  * AST: Added ``referencedDeclaration`` for enum members.
  * Code Generator: Fix internal error when functions are passed as parameters of other callables, when the function types can be implicitly converted, but not identical.
+ * Parser: Properly parse ``.address`` in some situations.
  * Type Checker: Make function-hash collision errors into fatal type errors.
 
 
diff --git a/libsolidity/parsing/Parser.cpp b/libsolidity/parsing/Parser.cpp
index 623060f0b..6dc0dfa6b 100644
--- a/libsolidity/parsing/Parser.cpp
+++ b/libsolidity/parsing/Parser.cpp
@@ -961,6 +961,14 @@ ASTPointer<Identifier> Parser::parseIdentifier()
 	return nodeFactory.createNode<Identifier>(expectIdentifierToken());
 }
 
+ASTPointer<Identifier> Parser::parseIdentifierOrAddress()
+{
+	RecursionGuard recursionGuard(*this);
+	ASTNodeFactory nodeFactory(*this);
+	nodeFactory.markEndPosition();
+	return nodeFactory.createNode<Identifier>(expectIdentifierTokenOrAddress());
+}
+
 ASTPointer<UserDefinedTypeName> Parser::parseUserDefinedTypeName()
 {
 	ASTNodeFactory nodeFactory(*this);
@@ -979,7 +987,7 @@ ASTPointer<IdentifierPath> Parser::parseIdentifierPath()
 	{
 		m_scanner->next();
 		nodeFactory.markEndPosition();
-		identifierPath.push_back(*expectIdentifierToken());
+		identifierPath.push_back(*expectIdentifierTokenOrAddress());
 	}
 	return nodeFactory.createNode<IdentifierPath>(identifierPath);
 }
@@ -1751,13 +1759,7 @@ ASTPointer<Expression> Parser::parseLeftHandSideExpression(
 		{
 			m_scanner->next();
 			nodeFactory.markEndPosition();
-			if (m_scanner->currentToken() == Token::Address)
-			{
-				expression = nodeFactory.createNode<MemberAccess>(expression, make_shared<ASTString>("address"));
-				m_scanner->next();
-			}
-			else
-				expression = nodeFactory.createNode<MemberAccess>(expression, expectIdentifierToken());
+			expression = nodeFactory.createNode<MemberAccess>(expression, expectIdentifierTokenOrAddress());
 			break;
 		}
 		case Token::LParen:
@@ -2081,7 +2083,7 @@ Parser::IndexAccessedPath Parser::parseIndexAccessedPath()
 		while (m_scanner->currentToken() == Token::Period)
 		{
 			m_scanner->next();
-			iap.path.push_back(parseIdentifier());
+			iap.path.push_back(parseIdentifierOrAddress());
 		}
 	}
 	else
@@ -2199,11 +2201,26 @@ ASTPointer<ParameterList> Parser::createEmptyParameterList()
 
 ASTPointer<ASTString> Parser::expectIdentifierToken()
 {
-	// do not advance on success
-	expectToken(Token::Identifier, false);
+	expectToken(Token::Identifier, false /* do not advance */);
 	return getLiteralAndAdvance();
 }
 
+ASTPointer<ASTString> Parser::expectIdentifierTokenOrAddress()
+{
+	ASTPointer<ASTString> result;
+	if (m_scanner->currentToken() == Token::Address)
+	{
+		result = make_shared<ASTString>("address");
+		m_scanner->next();
+	}
+	else
+	{
+		expectToken(Token::Identifier, false /* do not advance */);
+		result = getLiteralAndAdvance();
+	}
+	return result;
+}
+
 ASTPointer<ASTString> Parser::getLiteralAndAdvance()
 {
 	ASTPointer<ASTString> identifier = make_shared<ASTString>(m_scanner->currentLiteral());
diff --git a/libsolidity/parsing/Parser.h b/libsolidity/parsing/Parser.h
index 77152d38f..77d6cd17c 100644
--- a/libsolidity/parsing/Parser.h
+++ b/libsolidity/parsing/Parser.h
@@ -105,6 +105,7 @@ private:
 	ASTPointer<UsingForDirective> parseUsingDirective();
 	ASTPointer<ModifierInvocation> parseModifierInvocation();
 	ASTPointer<Identifier> parseIdentifier();
+	ASTPointer<Identifier> parseIdentifierOrAddress();
 	ASTPointer<UserDefinedTypeName> parseUserDefinedTypeName();
 	ASTPointer<IdentifierPath> parseIdentifierPath();
 	ASTPointer<TypeName> parseTypeNameSuffix(ASTPointer<TypeName> type, ASTNodeFactory& nodeFactory);
@@ -201,6 +202,7 @@ private:
 	ASTPointer<Expression> expressionFromIndexAccessStructure(IndexAccessedPath const& _pathAndIndices);
 
 	ASTPointer<ASTString> expectIdentifierToken();
+	ASTPointer<ASTString> expectIdentifierTokenOrAddress();
 	ASTPointer<ASTString> getLiteralAndAdvance();
 	///@}
 
diff --git a/test/libsolidity/semanticTests/functionTypes/address_member.sol b/test/libsolidity/semanticTests/functionTypes/address_member.sol
new file mode 100644
index 000000000..38b01db73
--- /dev/null
+++ b/test/libsolidity/semanticTests/functionTypes/address_member.sol
@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (address a1, address a2) {
+        a1 = this.f.address;
+        this.f.address;
+        [this.f.address][0];
+        a2 = [this.f.address][0];
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// f() -> 90572315268751552425567948436632610904688605307, 90572315268751552425567948436632610904688605307